GM Service Manual Online
For 1990-2009 cars only

    Object Number: 667477  Size: SH
  1. Rotate the crankshaft to bring the number 1 cylinder at the top dead center of the compression stroke. The number 1 cylinder is the front cylinder on the right bank. The mark on the crankshaft balancer should be aligned with the mark on the engine.

  2. Object Number: 663897  Size: SH
  3. Loosen the valve adjusting screws.
  4. Insert a feeler gauge between the tip of the rocker arm and the valve bridge.
  5. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 663110  Size: SH
  6. Adjust the valve lash to 0.3 mm (0.012 in). Refer to Valve Clearance Adjustment Specifications to determine which valves that can be adjusted when the engine is at Top Dead Center. Tighten the valve lash lock nut to 22 N·m (16 lb ft).

  7. Object Number: 667477  Size: SH
  8. Rotate the crankshaft one revolution to bring the number 1 cylinder at Top Dead Center of the exhaust stroke.

  9. Object Number: 660548  Size: SH
  10. Adjust the valve lash to 0.3 mm (0.012 in). Refer to Valve Clearance Adjustment Specifications to determine which valves that can be adjusted when the engine is at Top Dead Center. Tighten the valve lash lock nut to 22 N·m (16 lb ft).